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Article Released Thu-11th-February-2010 10:34 GMT
Contact: Ruth Institution: Nature Publishing Group
 IPCC: Cherish it, tweak it or scrap it?

Summaries of newsworthy papers: Why benzodiazepines can be addictive, A framework for future research and assessment, Gas-rich early galaxies, Protein link to insulin production, Grass genome sequenced, Ferroelectricity in a simple molecular crystal, Zonal flow in the Earth’s core and Direct mass measurements beyond uranium


This press release is copyright Nature.

VOL.463 NO.7282 DATED 11 FEBRUARY 2010

This press release contains:

· Summaries of newsworthy papers:

Neuroscience: Why benzodiazepines can be addictive

Climate: A framework for future research and assessment

IPCC: Cherish it, tweak it or scrap it?

Astronomy: Gas-rich early galaxies

Biology: Protein link to insulin production

Genetics: Grass genome sequenced

Materials science: Ferroelectricity in a simple molecular crystal

Geophysics: Zonal flow in the Earth’s core

And finally… Direct mass measurements beyond uranium

· Mention of papers to be published at the same time with the same embargo

· Geographical listing of authors

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[1] Neuroscience: Why benzodiazepines can be addictive (pp 769-774; N&V)

Benzodiazepines share a common neural reward pathway with addictive drugs, a Nature paper suggests. The finding helps explain why benzodiazepines can sometimes be addictive, and may aid the design of non-addictive alternatives.

It's known that benzodiazepines, such as diazepam, exert their calming effects by enhancing the action of the neurotransmitter gamma-aminobutyric acid (GABA). Christian Lüscher and colleagues now show that this GABA receptor activation boosts dopamine levels within well-characterised neural circuits that are typically targeted by other addictive drugs, such as opioids and cannabinoids.

The effect seems to be dependent on the ability of benzodiazepines to bind to a particular part of a particular GABA receptor — the alpha1 subunit of the GABA type A receptor. So, subunit-selective benzodiazepines that bind elsewhere on the molecule may offer therapeutic benefits without the addictive side-effects.

Christian Lüscher (University of Geneva, Switzerland)
Tel: +41 22 379 54 23; E-mail:

Peter Kalivas (Medical University of South Carolina, Charleston, SC, USA) N&V author
Tel: +1 843 792 4400; E-mail:

[2] Climate: A framework for future research and assessment (pp 747-756)

A new generation of plausible future climate pathways is needed to improve understanding of potential climate and socio-economic outcomes, suggests a Perspectives article in Nature. Richard Moss and colleagues describe a coordinated approach for developing and applying different ‘scenarios’ in climate change research, in order to foster increased collaboration between scientists and ultimately be more useful to decision makers.

Climate change scenarios are used to provide policy makers with a range of uncertainty, not to serve as crystal balls. Until now, model-based scenarios have used a step-by-step, sequential process between loosely connected disciplines. The disciplinary disconnect has led to inconsistent use of scenarios in policy-relevant assessment reports like those by the Intergovernmental Panel on Climate Change.

With nearly a decade of new economic data, emerging technologies and updated environmental observations, there is now a shift in focus towards a ‘parallel’ approach to developing scenarios. Central to this process are four new ‘representative concentration pathways’, which will provide a framework for modelling, increased collaboration and timely incorporation into climate research. These pathways span the range of radiative forcing scenarios, consisting of one rising scenario, two which stabilize, and one which peaks and later declines.

This new integrated approach will provide valuable insights into the interaction of natural and human-induced climate processes, and the potential costs and benefits of different mixes of adaptation and mitigation policy.

Richard Moss (University of Maryland, College Park, MA, USA)
Tel: +1 301 314 6711; E-mail:

IPCC: Cherish it, tweak it or scrap it? (pp 730-732)

As calls for reform intensify following recent furores about e-mails, conflicts of interest, glaciers and extreme weather, five influential climatologists propose ways forward for the Intergovernmental Panel on Climate Change (IPCC). Their suggestions, published in Nature’s Opinions section this week, range from reaffirming the volunteer organisation’s best practice, to replacing it with a staffed structure like that of the International Atomic Energy Agency. Mike Hulme proposes dissolving the IPCC after the Fifth Assessment Report in 2014 into “three types of assessment and evaluation”. John Christy says that something more like Wikipedia would better reflect the heterogeneity of scientific opinion. Eduardo Zorita calls for the creation of an international climate agency, with a full-time staff of around 200 scientists independent of government, industry and academia. Jeff Price meanwhile urges the IPCC to improve its author and reviewer choice, and to produce annual dispatches. Finally, Thomas Stocker asserts that the governing principles of the IPCC are still sound, if strictly adhered to. He concludes “the requirement that assessments are policy relevant but never policy prescriptive, is of paramount importance”.


Mike Hulme (University of East Anglia, Norwich, UK)
Tel: +44 1603 593162; E-mail:

John Christy (University of Alabama, Huntsville, AL, USA)
Tel: +1 256 961 7763; E-mail: christy@nsstc.uah.ed

Thomas Stocker (University of Bern, Switzerland)
Tel: +41 31 631 44 62; E-mail:

Eduardo Zorita (GKSS Research Center, Geesthacht, Germany)
Tel: +49 4152 87-1856; E-mail:

Jeff Price (World Wildlife Fund US, USA)
Tel: +1 202 460 0208; E-mail:

[3] Astronomy: Gas-rich early galaxies (pp 781-784; N&V)

Typical star-forming galaxies in the early Universe contained three to ten times more molecular gas than their counterparts today, according to observations published in this week's Nature. This finding explains the high rate of star formation in these early galaxies, without having to invoke any change in star-forming efficiency.

Typical massive galaxies in the distant (and therefore early) Universe formed stars an order of magnitude more rapidly than do similar galaxies today. This implies either that star formation was significantly more efficient in early times, or that the raw material for star formation — cold molecular gas — was more plentiful in early star-forming galaxies. These two possibilities have been difficult to distinguish, because until now observations of molecular gas in the distant Universe have largely been restricted to very luminous objects, such as quasars or merging galaxies, which are not representative of more normal star-forming galaxies.

Linda Tacconi and colleagues have taken advantage of recent improvements in instrumental sensitivity to measure molecular gas contents in typical star-forming galaxies at two past epochs: when the Universe was about 24% and 40% of its current age. At these times, the sampled galaxies contained, respectively, about 44% and 34% cold gas, as compared with about 3–10% for today's massive spiral galaxies — providing a natural explanation for today's much lower star formation rate.

Linda Tacconi (Max-Planck-Institute für extraterrestrische Physikfor Extraterrestrial Physics, Garching, Germany)
Tel: +49 89 30000 3873; E-mail:

Andrew Blain (California Institute of Technology, Pasadena, CA, USA) N&V author
Tel: +1 626 395 4726; E-mail:

[4] Biology: Protein link to insulin production (pp 775-780)

A protein called Rfx6 directs the formation of insulin-producing islet cells in humans and mice, a Nature study suggests. The finding has relevance for our understanding of diabetes, and may help the therapeutic production of new insulin-producing cells for diabetic patients.

Mice lacking Rfx6 fail to produce most of the normal range of islet cell types, Michael German and colleagues demonstrate. And in human infants, mutations in RFX6 are shown to underlie a recessive syndrome of neonatal diabetes.

Michael German (University of California San Francisco, CA, USA)
Tel: +1 415 476 9262; E-mail:

[5] Genetics: Grass genome sequenced (pp 763-768)

The genome of the wild grass Brachypodium distachyon (Brachypodium) is revealed in this week’s Nature. It is the first member of the economically important Pooideae subfamily, which includes wheat and barley, to have its DNA fully sequenced.

Michael Bevan and colleagues went on to compare the genomes of Brachypodium, rice and sorghum, revealing how grass genomes have evolved over time, and establishing a template for future analyses of large, complex grass genomes, such as wheat.

Brachypodium is a wild annual grass endemic to the Mediterranean and Middle East, and shows promise as a model organism because it is small, grows quickly, and is easy to cultivate and manipulate in the laboratory. The high-quality genome sequence should help Brachypodium reach its potential as an important experimental system for developing new energy and food crops.

Michael Bevan (John Innes Centre, Norwich, UK)
Tel: +44 1603 450 520; E-mail:

[6] Materials science: Ferroelectricity in a simple molecular crystal (pp 789-792)

Ferroelectricity — the ability to store and switch an electrical polarization — has been demonstrated in crystals of a very simple organic molecule, containing only carbon, hydrogen and oxygen. The ferroelectric properties — a high polarization that is easily switchable, and persists to well above room temperature — are good enough to envisage applications in organic electronics.

Ferroelectric materials have many applications in electronic circuits, notably in tunable capacitors and random access memories. Organic molecules exhibiting ferroelectricity have been known since 1920, but organic ferroelectrics with practical potential have been mostly limited to polymers and other complex materials.

In this week’s Nature, Sachio Horiuchi and colleagues report their discovery of pronounced ferroelectricity in crystals of the molecule croconic acid. The electrical polarization originates in an ordered network of hydrogen bonds in the crystal, with the switching accomplished by the simultaneous transfer of protons from one side of each molecule to the other. The robustness of the ferroelectricity and the ease of switching make the molecule attractive for applications, and the discovery of ferroelectricity in such a simple organic molecule suggests that organic ferroelectrics may not be as rare as has been thought.

Sachio Horiuchi (National Institute of Advanced Industrial Science and Technology, Ibaraki, Japan)
Tel: +81 298 61 2945; E-mail:

[7] Geophysics: Zonal flow in the Earth’s core (pp 793-796)

Scientists have identified a jet stream in the Earth’s outer core using computer simulations of zonal flow. The flow could provide an explanation for the westward drift of the Earth’s magnetic field.

Zonal flows or jets are often spontaneously generated in turbulent systems, such as in oceans, nuclear fusion devices or the atmospheres of giant planets. The Earth’s liquid iron outer core is also believed to be in a turbulent state — convecting fluids affected by the planet’s rotation produce a magnetic field, which is stabilized by the solid inner core.

To investigate whether zonal flow exists in the Earth’s outer core, Akira Kageyama and colleagues used large-scale computer simulations to conduct a geodynamo experiment at low viscosities. They identified a new convection current with a dual structure — inner sheet-like radial plumes, surrounded by westward cylindrical zonal flow. This flow is similar to flows observed in planetary atmospheres of the Solar System, such as Jupiter’s, and is stable under a self-generated, strong dipole magnetic field.

Akira Kageyama (Kobe University, Japan)
Tel: +81 78 803 6034; E-mail:

[8] And finally… Direct mass measurements beyond uranium (pp 785-788; N&V)

The first direct mass measurements of an element heavier than uranium are reported in this week’s Nature. The results, obtained for isotopes of nobelium collected in an electromagnetic trap, provide accurate values of the binding energies of heavy nuclei, which are crucial for understanding the structure of superheavy elements.

The mass of an atomic nucleus differs from that of its constituent protons and neutrons by an amount equivalent to the energy that holds the nucleus together — the nuclear binding energy. This is the energy released in nuclear reactions, and it determines the stability of atomic nuclei. An accurate knowledge of binding energies for nuclei with more than 100 protons (uranium has 92) is needed to constrain predictions of an ‘island of stability’ of superheavy elements.

Until now, the masses of elements beyond uranium have been inferred from measurements of their radioactive decay products — an indirect method that can introduce significant uncertainties in the calculated binding energies. Michael Block and colleagues have used an ion-trap mass spectrometer to collect ions of three isotopes of nobelium (with 102 protons and 150–152 neutrons) and measure their masses directly. The results provide accurate reference points for theoretical models, and reliable anchors for inferring the masses of still heavier elements.

Michael Block (GSI, Darmstadt, Germany)
Tel: +49 6159 71 1609; E-mail:

Georg Bollen (Michigan State University, East Lansing, MI, USA) N&V author
Tel: +1 517 333 6435; E-mail:


[9] Mical links semaphorins to F-actin disassembly (pp 823-827)


***This paper will be published electronically on Nature's website on 10 February at 1800 London time / 1300 US Eastern time (which is also when the embargo lifts) as part of our AOP (ahead of print) programme. Although we have included it on this release to avoid multiple mailings it will not appear in print on 11 February, but at a later date. ***

[10] Arthropod relationships revealed by phylogenomic analysis of nuclear protein-coding sequences
DOI: 10.1038/nature08742


The following list of places refers to the whereabouts of authors on the papers numbered in this release. For example, London: 4 - this means that on paper number four, there will be at least one author affiliated to an institute or company in London. The listing may be for an author's main affiliation, or for a place where they are working temporarily. Please see the PDF of the paper for full details.

Laxenburg: 2
Vienna: 2

Brussels: 4
Gent: 5

Pelotas: 5

London: 4
Montreal: 4
Vancouver: 4

Beijing: 5

Frederiksberg: 5

Helsinki: 2, 5
Jyvaskyla: 8

Amiens: 5
Clermont-Ferrand: 5
Evry: 5
Gif-sur-Yvette: 3
Grenoble: 3
Lille: 4
Paris: 3
Strasbourg: 5
Versailles: 5

Darmstadt: 8
Garching: 3, 8
Giessen: 8
Greifswald: 8
Heidelberg: 8
Mainz: 8
Munich: 3, 5
Neuherberg: 5

Tel Aviv: 3

Bari: 4
L’Aquila: 6
Padova: 8

Kobe: 7
Saitama: 6
Tokyo: 6
Tsukuba: 2, 6
Yokohama: 7

Yongin: 5

Bilthoven: 2
Dreijenlaan: 9
Leiden: 6
Wageningen: 9

Wellington: 2

Katowice: 5

Dubna: 8
Gatchina: 8

Alcala de Henares-Madrid: 3
Granada: 8

Geneva: 1
Zurich: 1, 5

Istanbul: 5

Exeter: 2
Norwich: 5


Huntsville: 5

Tucson: 3

Albany: 5
Berkeley: 3, 5
Davis: 5
Emeryville: 5
Hayward: 4
La Jolla: 5
Los Angeles: 3, 10
San Francisco: 4
Stanford: 2
Walnut Creek: 5

Boulder: 2

Newark: 5

District of Columbia
Washington: 2

Gainsville: 5

Normal: 5

West Lafayette: 5

Ames: 5

College Park: 2, 3, 10

Amherst: 5
Belmont: 1

East Lansing: 5

St Paul: 5

St Louis: 5

New Jersey
Piscataway: 5
Princeton: 2

New Mexico
Los Alamos: 8
Santa Fe: 5

New York
Ithaca: 5

North Carolina
Durham: 10

Columbus: 5

Corvallis: 5

Oak Ridge: 2, 5

Arlington: 5
Dallas: 9

Pullman: 5

West Virginia
Kearneysville: 5

Madison: 5


From North America and Canada
Neda Afsarmanesh, Nature New York
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From Japan, Korea, China, Singapore and Taiwan
Mika Nakano, Nature Tokyo
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From the UK
Rachel Twinn, Nature, London
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